> If this is true then how is it single cell animals can continue to make
copies of it > self without dividing the species into oblivion?
The answer to this question depends on the single cell organisms that you
are refering to. Telomere shortening occurs at the ends of linear
chromosomes because the DNA replication machinery is unable to synthesize
the terminal portion.
Prokaryotes, which posses a circular genome, lack chromosome ends and thus
avoids the problem entirely.
Single cell eukaryotes, such as yeast, experience telomere erosion but
posses enzymes that repair the loss, thus maintaining a stable telomere
length.
Cheers,
Wally